Question

Evaluate the expression for the given value of the variable. Show your work.

[-4b-8]+[-1-b^2]+2b^3;b=-2



Solve the equation. Check for extraneous solutions. 9[9-8x]=2x+3. Show your work.



I really need help with both of these problems.

Answer 1

If b = -2, then since
(-2)^2 = (-2)(-2) = +4
(-2)^3 = (-2)(-2)(-2) = -8

[-4b-8]+[-1-b^2]+2b^3
= [-4(-2)-8]+[-1-(-2)^2]+2(-2)^3
= [8-8]+[-1-4]+2(-8)
= 0-5-16
= -21

9[9-8x] = 2x+3
81-72x = 2x+3
78 = 74x
x = 78/74 = 39/37